POPE COUNTY, Ark. (KTHV) - Pope County search crews call it quits for the night after spending all day Tuesday looking for a missing man in Lake Dardanelle.

Pope County authorities are not releasing the missing man's name yet. They will only say he's 20-years-old and from Heber Springs. The missing man was in a pick-up truck involved in a one-vehicleaccident along Interstate 40, ending with that truck, landing in the lake.

A median along Interstate 40 became basecamp Tuesday for Pope County emergency workers, searching for a missing 20-year-old man in Lake Dardanelle.

"The report was a vehicle had run off from the median into the lake," Sheriff Aaron Duvall said.

Sheriff Duvall says the missing man was a passenger in a pick-up truck, traveling I-40 Eastbound close to midnight Tuesday. The 24-year-old driver turned up later after calling 911 at a nearby motel. The sheriff says he has some cuts but was treated and released from the hospital.

"According to the person who escaped they were Heber Springs,"Sheriff Duvall said.

"And were they on their way home? THV's Max Seigle asks.

"Yes," the sheriff replied.

State police on scene say that preliminary reports show alcohol and speed do not appear to be factors here but the cause of the accident remains under investigation.

"The sheriff's office has an underwater robot that we are using at this time, in fact we used it to discover where the vehicle was on Tuesday morning," Sheriff Duvall said.

Sheriff Duvall says that robot sends images to a computer, which wassurrounded by emergency personnel Tuesday looking for leads. He wouldn't let our cameras shoot the screen but says the pictures capture a look some 25 to 30 feet underwater.

"We have the dive team on stand-by ready to go if anything is indicated," Sheriff Duvall said.

It's a helpful tool and crew, scouring this lake, with no official call yet on a rescue or recovery.

"Right now, it's just to see if we can locate this victim," Sheriff Duvall said.

And the sheriff says that they're not making a formal call on this search right now out of respect for the victim's family. He told us that family members were on the scene Tuesday and he just didn't want to get into that while they were nearby.

Sheriff Duvall says his crews also received helpTuesday from Johnson County. And Arkansas Game and Fish is on standby with a dive team. The search will resume tomorrow morning.

The sheriff did have any information on the relationship between the two men in the accident or where they were coming from at the time.